The present invention relates to continuous ink jet printers and more particularly to interconnection technology for ink jet charge plates for such printers.
In continuous ink jet printing, ink is supplied under pressure to a manifold that distributes the ink to a plurality of orifices, typically arranged in linear array(s). The ink is expelled from the orifices in jets which break up due to surface tension in the ink into droplet streams. Ink jet printing is accomplished with these droplet streams by selectively charging and deflecting some droplets from their normal trajectories. The deflected or undeflected droplets are caught and re-circulated and the others are allowed to impinge on a printing surface.
Planar charge plate structures have been utilized for many years for continuous ink jet printheads. In existing ink jet printing systems, the planar charging assembly consists of three units. These three units include flat charge plate leads bonded to a flat rigid ceramic material; charge drivers and circuitry on a rigid printed circuit board; and a flexible circuit to connect the charge leads of the charge plate to the driver circuit board. Electroformed charge plate coupons are disclosed in U.S. Pat. Nos. 4,560,991, and 5,512,117, fully incorporated by reference herein. Charge plate coupons consisting of nickel leads pattern plated onto a sacrificial, selectively etchable substrate are attached nickel-lead-down to a dielectric substrate. The sacrificial copper is then etched away, leaving the discrete nickel leads bonded to the flat, rigid substrate. The leads on the charge plate must then have a mating flex circuit to bridge to a separate charge driver electronics board.
It would be desirable to have an improvement of the flat face charging concept, wherein the flex cable is made as an integral part of the charge plate coupon, thus eliminating a separate flex cable and the required assembly thereof.
It is the object of the present invention to provide an improvement of the flat face charging concept, wherein the flex cable is made as an integral part of the charge plate coupon. This arrangement eliminates the need for a separate flex cable and the required assembly thereof.
In accordance with one aspect of the present invention, a method is provided for making a charging electrode structure for flexible electrical connection between charging electrodes and control electronics. Initially, an electrode structure is electroformed onto a sacrificial metallic substrate. A first portion of the electrode structure forms the charging electrodes, and a second portion of the electrode structure forms the flexible electrical connection. The second portion of the electrode structure is then laminated to a flexible carrier film, while the first portion of the electrode structure is laminated to a rigid, dielectric substrate. Then the sacrificial metallic substrate is removed.
Other objects and advantages of the invention will be apparent from the following description and the appended claims.